Dextromethorphan and quinidine and Methamphetamine interaction
Dextromethorphan and quinidine and Methamphetamine: the Methamphetamine prescribing label flags this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Methamphetamine (Methamphetamine Hydrochloride) label · effective 2025-11-07
Serotonin Syndrome: Increased risk when coadministered with serotonergic agents (e.g., SSRIs, SNRIs, triptans), but also during overdosage situations.
Serotonin Syndrome Serotonin syndrome, a potentially life-threatening reaction, may occur when amphetamines are used in combination with other drugs that affect the serotonergic neurotransmitter systems such as monoamine oxidase inhibitors (MAOIs), selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), triptans,…
If serotonin syndrome occurs, discontinue methamphetamine hydrochloride tablets, USP and the concomitant serotonergic drug(s) [see Warnings and Precautions 5.8].
If serotonin syndrome occurs, discontinue methamphetamine hydrochloride tablets, USP and the CYP2D6 inhibitor [see Warnings and Precautions 5.8].
The coadministration with cytochrome P450 2D6 (CYP2D6) inhibitors may also increase the risk with increased exposure to methamphetamine.
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.